Move is_block to lower in the call tree

2 files changed, 43 insertions, 54 deletions

diff --git a/crates/ra_syntax/src/grammar/expressions.rs b/crates/ra_syntax/src/grammar/expressions.rs
index 9d75bfb90..5f5a3077d 100644
--- a/crates/ra_syntax/src/grammar/expressions.rs
+++ b/crates/ra_syntax/src/grammar/expressions.rs
@@ -64,6 +64,16 @@ pub(crate) fn block(p: &mut Parser) {
                         if p.at(R_CURLY) {
                             m.abandon(p);
                         } else {
+                            // test no_semi_after_block
+                            // fn foo() {
+                            //     if true {}
+                            //     loop {}
+                            //     match () {}
+                            //     while true {}
+                            //     for _ in () {}
+                            //     {}
+                            //     {}
+                            // }
                             if is_blocklike {
                                 p.eat(SEMI);
                             } else {
@@ -158,19 +168,18 @@ fn current_op(p: &Parser) -> (u8, Op) {
 // Parses expression with binding power of at least bp.
 fn expr_bp(p: &mut Parser, r: Restrictions, bp: u8) -> BlockLike {
     let mut lhs = match lhs(p, r) {
-        (Some(lhs), macro_blocklike) => {
+        Some((lhs, macro_blocklike)) => {
             // test stmt_bin_expr_ambiguity
             // fn foo() {
             //     let _ = {1} & 2;
             //     {1} &2;
             // }
-            if r.prefer_stmt && (is_block(lhs.kind()) || macro_blocklike == Some(BlockLike::Block))
-            {
+            if r.prefer_stmt && macro_blocklike.is_block() {
                 return BlockLike::Block;
             }
             lhs
         }
-        (None, _) => return BlockLike::NotBlock,
+        None => return BlockLike::NotBlock,
     };
 
     loop {
@@ -192,29 +201,12 @@ fn expr_bp(p: &mut Parser, r: Restrictions, bp: u8) -> BlockLike {
     BlockLike::NotBlock
 }
 
-// test no_semi_after_block
-// fn foo() {
-//     if true {}
-//     loop {}
-//     match () {}
-//     while true {}
-//     for _ in () {}
-//     {}
-//     {}
-// }
-fn is_block(kind: SyntaxKind) -> bool {
-    match kind {
-        IF_EXPR | WHILE_EXPR | FOR_EXPR | LOOP_EXPR | MATCH_EXPR | BLOCK_EXPR => true,
-        _ => false,
-    }
-}
-
 const LHS_FIRST: TokenSet = token_set_union![
     token_set![AMP, STAR, EXCL, DOTDOT, MINUS],
     atom::ATOM_EXPR_FIRST,
 ];
 
-fn lhs(p: &mut Parser, r: Restrictions) -> (Option<CompletedMarker>, Option<BlockLike>) {
+fn lhs(p: &mut Parser, r: Restrictions) -> Option<(CompletedMarker, BlockLike)> {
     let m;
     let kind = match p.current() {
         // test ref_expr
@@ -247,30 +239,28 @@ fn lhs(p: &mut Parser, r: Restrictions) -> (Option<CompletedMarker>, Option<Bloc
             if p.at_ts(EXPR_FIRST) {
                 expr_bp(p, r, 2);
             }
-            return (Some(m.complete(p, RANGE_EXPR)), None);
+            return Some((m.complete(p, RANGE_EXPR), BlockLike::NotBlock));
         }
         _ => {
-            let (lhs_marker, macro_block_like) = atom::atom_expr(p, r);
-
-            if macro_block_like == Some(BlockLike::Block) {
-                return (lhs_marker, macro_block_like);
-            }
-            if let Some(lhs_marker) = lhs_marker {
-                return (Some(postfix_expr(p, r, lhs_marker)), macro_block_like);
-            } else {
-                return (None, None);
-            }
+            let (lhs, blocklike) = atom::atom_expr(p, r)?;
+            return Some((
+                postfix_expr(p, lhs, !(r.prefer_stmt && blocklike.is_block())),
+                blocklike,
+            ));
         }
     };
     expr_bp(p, r, 255);
-    (Some(m.complete(p, kind)), None)
+    Some((m.complete(p, kind), BlockLike::NotBlock))
 }
 
-fn postfix_expr(p: &mut Parser, r: Restrictions, mut lhs: CompletedMarker) -> CompletedMarker {
+fn postfix_expr(
+    p: &mut Parser,
+    mut lhs: CompletedMarker,
     // Calls are disallowed if the type is a block and we prefer statements because the call cannot be disambiguated from a tuple
     // E.g. `while true {break}();` is parsed as
     // `while true {break}; ();`
-    let mut allow_calls = !r.prefer_stmt || !is_block(lhs.kind());
+    mut allow_calls: bool,
+) -> CompletedMarker {
     loop {
         lhs = match p.current() {
             // test stmt_postfix_expr_ambiguity
@@ -418,22 +408,21 @@ fn arg_list(p: &mut Parser) {
 //     let _ = ::a::<b>;
 //     let _ = format!();
 // }
-fn path_expr(p: &mut Parser, r: Restrictions) -> (CompletedMarker, Option<BlockLike>) {
+fn path_expr(p: &mut Parser, r: Restrictions) -> (CompletedMarker, BlockLike) {
     assert!(paths::is_path_start(p) || p.at(L_ANGLE));
     let m = p.start();
     paths::expr_path(p);
-    let res = match p.current() {
+    match p.current() {
         L_CURLY if !r.forbid_structs => {
             named_field_list(p);
-            m.complete(p, STRUCT_LIT)
+            (m.complete(p, STRUCT_LIT), BlockLike::Block)
         }
         EXCL => {
-            let block_like = items::macro_call_after_excl(p); // TODO: Use return type (BlockLike)
-            return (m.complete(p, MACRO_CALL), Some(block_like));
+            let block_like = items::macro_call_after_excl(p);
+            return (m.complete(p, MACRO_CALL), block_like);
         }
-        _ => m.complete(p, PATH_EXPR),
-    };
-    (res, None)
+        _ => (m.complete(p, PATH_EXPR), BlockLike::NotBlock),
+    }
 }
 
 // test struct_lit
diff --git a/crates/ra_syntax/src/grammar/expressions/atom.rs b/crates/ra_syntax/src/grammar/expressions/atom.rs
index 471f398f5..a976799e7 100644
--- a/crates/ra_syntax/src/grammar/expressions/atom.rs
+++ b/crates/ra_syntax/src/grammar/expressions/atom.rs
@@ -61,16 +61,12 @@ pub(super) const ATOM_EXPR_FIRST: TokenSet = token_set_union![
 
 const EXPR_RECOVERY_SET: TokenSet = token_set![LET_KW];
 
-pub(super) fn atom_expr(
-    p: &mut Parser,
-    r: Restrictions,
-) -> (Option<CompletedMarker>, Option<BlockLike>) {
+pub(super) fn atom_expr(p: &mut Parser, r: Restrictions) -> Option<(CompletedMarker, BlockLike)> {
     if let Some(m) = literal(p) {
-        return (Some(m), None);
+        return Some((m, BlockLike::NotBlock));
     }
     if paths::is_path_start(p) || p.at(L_ANGLE) {
-        let path_expr = path_expr(p, r);
-        return (Some(path_expr.0), path_expr.1);
+        return Some(path_expr(p, r));
     }
     let la = p.nth(1);
     let done = match p.current() {
@@ -98,7 +94,7 @@ pub(super) fn atom_expr(
                     // }
                     p.error("expected a loop");
                     m.complete(p, ERROR);
-                    return (None, None);
+                    return None;
                 }
             }
         }
@@ -115,10 +111,14 @@ pub(super) fn atom_expr(
         BREAK_KW => break_expr(p),
         _ => {
             p.err_recover("expected expression", EXPR_RECOVERY_SET);
-            return (None, None);
+            return None;
         }
     };
-    (Some(done), None)
+    let blocklike = match done.kind() {
+        IF_EXPR | WHILE_EXPR | FOR_EXPR | LOOP_EXPR | MATCH_EXPR | BLOCK_EXPR => BlockLike::Block,
+        _ => BlockLike::NotBlock,
+    };
+    Some((done, blocklike))
 }
 
 // test tuple_expr